title: Effect of base metal alloys recasting on marginal integrity of castable crowns.
abstract: BACKGROUND
  Base metals have a wide use in casting methods. Sometimes they are reused in laboratories which may have an adverse effect on the restoration marginal integrity. This study aimed to investigate the effect of recasting of alloys on marginal integrity of restorations.
  
  
  METHODS
  Models with two types of finishing lines shoulder bevel 45° and shoulder 135° were produced and 15 wax copings were formed on each one of them. Each group containing 15 copings was divided into three subgroups A, B and C. Group A was casted with 100% new alloy, group B with 50% new and 50% recasted alloy and group C with 100% recasted alloy. Obtained metal copings were placed on dies and marginal gap size between restoration margin and the dies finishing line was measured using metric microscope and Moticam camera in four points, buccal, lingual, mesial and distal.
  
  
  RESULTS
  A significant difference in mean marginal gap size exists among three types of alloys used (p-value = 0.036). A significant difference is observed between mean marginal gap size of two types of finishing lines for different alloys (p-value = 0.001).
  
  
  CONCLUSIONS
  Using 100% recasted alloy is not recommended for any of the two types of finishing lines.
authors.affiliation: Department of Prosthodontics, School of Dentistry, Torabinejad Dental Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Farshad
authors.initials: F
authors.lastname: Bajoghli
authors.forename: Saeid
authors.initials: S
authors.lastname: Nosouhian
authors.forename: Hamid
authors.initials: H
authors.lastname: Badrian
authors.forename: Hossein
authors.initials: H
authors.lastname: Goroohi
authors.forename: Amir
authors.initials: A
authors.lastname: Saberian
authors.forename: Leyla
authors.initials: L
authors.lastname: Gadesi
mesh_terms: D001641:Bicuspid; D002858:Chromium Alloys / Q000737:chemistry*; D003442:Crowns; D003734:Dental Casting Investment / Q000737:chemistry*; D003735:Dental Casting Technique; D018772:Dental Marginal Adaptation; D017267:Dental Prosthesis Design; D017743:Equipment Reuse; D006801:Humans; D008422:Materials Testing; D013499:Surface Properties; D019231:Tooth Preparation, Prosthodontic
chemical_list: D002858:Chromium Alloys; D003734:Dental Casting Investment